A petroleum spill in water presents a special challenge for imaging systems based on visible detection methods. For example, ocean water is often turbid and appears dark to the eye, as does crude oil. Crude oil or diesel spills may float to the surface because of their lower density and may form well-defined films, especially in still waters. However, oil films may not show a strong contrast relative to the water surface itself, at least to the unaided eye. This may occur in water that is choppy or covered in waves, because the water surface may alternately look dark or light depending on how the water reflects the sky or the sun above it, thus masking low contrast oil-film areas. Accordingly, there exists a need for an improved imaging system that may be used for oil spill detection applications.